Any Ideas How to Remove Joining Compound

This is the stuff:D

http://www.elixair.co.uk/restore.htm

cheers baz

That brought back some memories. I’ve not seen NSN’s for nearly 18 years.

As an alternative to all those previously mentioned nasty solvents, CAREFUL application of a heat gun helps to loosen the grip of PRC. Keep in mind the possible annealing effect on aircraft alloys, dont set fire to the stuff like when you are trying to strip the paint off household woodwork..Beware of fumes etc

At the end of the day elbow grease lots of scrubbing, no easy way..appalling stuff. Only comes off easily when you are trying to seal a leak in a far corner of a fuel tank!

Chumpy.

I have always avoided heat guns for PRC (althought i have tried it and it works), mostly due to the fumes. I have been told that PRC “smoke” fumes are even more toxic than MEK and wet PRC together.

Hard work to remove the stuff whatever you do, but it it didn’t stick so bloody well, there would be no idea in using it in the first place 😉

As an alternative to all those previously mentioned nasty solvents, CAREFUL application of a heat gun helps to loosen the grip of PRC. Keep in mind the possible annealing effect on aircraft alloys, dont set fire to the stuff like when you are trying to strip the paint off household woodwork..Beware of fumes etc

At the end of the day elbow grease lots of scrubbing, no easy way..appalling stuff. Only comes off easily when you are trying to seal a leak in a far corner of a fuel tank!

Chumpy.

Surely those wipes are for wet sealent, or am I mistaken?

They probably are but the Skyrestore jelly is definitely for cured sealant ,I have used it and it does work,a limitation is possibly that it does need a contact time to work and therefore not suitable for inverted application.It is supposed to be ‘safer’ than solvents but to me anything that will attack PRC should be treated with caution.
Personally I am surprised that M.E.K is still available and should be used with Extreme caution,I do use it occasionally but only when no other option is available.
As I posted previously Skyrestore does not smell pleasant !!

cheers baz

Surely those wipes are for wet sealent, or am I mistaken?

What the RAF Use

We all now use lotox wipes for general cleaning and specifically skywipes not to be confused with skydrol from nimrods which will melt your hand

PM sent.

Hi Martin
I have sent a PM.
I have 2 gallons of MEK for you, just arrange to collect if you want it.

This computer will not let me edit…the link was on post 16

cheers baz

12 jag and myself have given the name of a fairly modern compound made SPECIFICALLY for removing PRC,it softens it to make scraping off (relatively )easy ,it does pong a bit,but is (allegedly !!) fairly safe to use.
There is absolutely no need to use solvents !!
Fuel tank sealant removal is more difficult because for obvious reasons you cannot use this stuff near an integral tank.
On post I put a direct link to one company who sell this compound.

cheers baz

Use a scraper to get the majority off then the residue with stuff a bit like the oasis blocks florists use will try too find out the name and supplier of it. Dont bother with sky restore only takes off a micron at a time and is way too nasty.

Definitly sounds like PRC. Best way to remove it is MEK, Light aero supplies sell it but it’s not cheap and you’ll need alot of it. It’ll melt PRC but you’ll need to get the excess off with a scraper before you use MEK. Been there done that, got the T-Shirt then put it all back with more PRC:D

LOL. A once only job for me hopefully. :p

Definitly sounds like PRC. Best way to remove it is MEK, Light aero supplies sell it but it’s not cheap and you’ll need alot of it. It’ll melt PRC but you’ll need to get the excess off with a scraper before you use MEK. Been there done that, got the T-Shirt then put it all back with more PRC:D

Old wood chisel and a garryson disk.

Roy used that approach to remove the gung round his Sea Hawk glazing (www.wv838.com).

Jon

Apart from acetone most effective solvents are not available at all any more,not green enough. If you do get hold of anything effective, the H&S bumf that comes with it will frighten most people off. Use all of it in a well ventillated area,as all petroleum based solvents are toxic and mnore or less narcotic-its all right nodding off due to tiredness,but falling down due to solvent abuse is harder to explain.

Oh!, regarding the removal.

Hard work and the scrapers mentioned about. MEK can be used to clean a surface once it has been scraped free, if it don’t kill you first. Not even sure MEK is available outside the industry.

Don’t experiment with different solvents. If its not in general use in the aerospace industry, it might be because it causes corrosion, or otherwise damage something. Use aerospace recommended solvents.

Wear a mp3 player and try to think of something else. Oh, and just wait untill you need to remove it from the fuel tanks…….

What you need to ask for is PR1422 B1/2 or A1/2. Depends on the drying time (B1/2 takes longer to set, but is a much better compound). Its a two part mix – if you get it in a tub, be warned, you’ll be stirring it for hours! If you manage to get it in the semkit its a much better way of applying, just don’t accidently unscrew the plunger while you are mixing… pump the plunger and twist it clockwise while you are doing it. It should usually take about 10 minutes of hard graft to get the stuff mixed properly…. oh, and wear gloves. Its nasty stuff…… stinks too….:D

Light Aero (LAS) sell it. Thats your sealant anyway…

To remove it, I echo what has been said before – MEK or Trichloroethane (Trike) – both of which will kill you horribly – and a non-metallic scraper… oh and alot of time….

Two things regarding the mixing:

First, be sure to mix it properly. The semkit can be attached to a slow turning drill, so you only need to do the pumping (keep the semkit cylinder fixed in a vice). You cant overmix (unless you spend so much time, that the stuff hardens), but you can undermix. I can’t recomend the tub type sealent, as the mixing is too difficult and messy.

Second, if you are using small amounts many times a day, dispose the semkit into a number of small plastic bags and keep these in the freezer. The sealent will stay fine for at least a day, or two (don’t let people tell you, that it lasts forever in the freezer). Just give it a few minutes to defrost. Cut a corner off the bag and use it as you would apply icing to a cake.

Final warning: this is toxic stuff. Wear protection and have proper ventilation. Also ensure that people around you are aware of the use, so they can protect themselves.

I normally apply a very percise amount on the job, then somehow manage to dispose the remaining compound onto my coveralls, shoes and gloves 😀

Thanks for the info from everyone.

I never thought that my simple question would receive so much debate and so many diff answers. 😉

Once again many thanks chaps 🙂

Hello. My Fathers company,Plasticon in Bolton,makes a very sharp perspex scraper for removing this sort of stuff for BAe. Im fairly certain he would do small batches if you asked him

Alternatively,most of us make our own scrapers out of old perspex pieces or other non metallic media,the Skyrestore does work but it does pong a bit;)
Somebody also manufactures a nylonish rotary tool,kind of like a plastic rotary wire brush.

cheers baz

Hello. My Fathers company,Plasticon in Bolton,makes a very sharp perspex scraper for removing this sort of stuff for BAe. Im fairly certain he would do small batches if you asked him

What a weird thread to drag some memories up with….. 😀

I have fond memories of that blasted PRC too…..

Mind you, found it just the stuff to use when it came to race prepping a car of mine….. amazing where I found uses for it, considering it was supplied courtesy of the RAF…. 😮